So often society tells us not to feel or think negative feelings or thoughts. It tells us if we think and feel positively all the time, all our problems will go away. This implies that all our problems are our fault: if we have problems then, society says, we must not be positive enough. So they implicitly say to the man who is blind since birth, "Serves you right!"
There's nothing wrong with these feelings. There is a reason we are capable of such feelings. They tell us that there is something to deal with. I believe that the best way to deal with these feelings is to embrace them and what they are trying to tell us, and then say to them, ”ok, you've done your job," and then let them go. But they won't go until they do their job, which is to tell us something. So the question is, what are these feelings trying to tell you?
A good way to answer that is talk through your feelings. If you feel that you can't talk to anyone, talking to an animal, even if stuffed, may help, or writing about it. This allows you to get the words out so that you can look at them from outside, and clarify your feelings and thoughts. Then, once you have clarified them, you can talk to other people more clearly. They may have ideas that you have not thought of or a fresh perspective. If you just need support, not advice, you might want to tell them right from the start what you need.
And then there is hope, that we can make it through these feelings, and maybe learn from them along the way. Society confuses hope with pretending we are always happy. What is there to hope for if we are perfectly happy?